I modified the base for the stepper motor and a 1:2 gear ratio.
I first printed out a bearing mount that will fit in the original hole. This was a bearing I had for an older helicopter. I would have taken the bearing out of my sons fidget spinner but I could not find it.
Next, I used Fusion 360 to print out 2:1 gears on my SLA printer. And mounted the stepper motor in the correct position to mesh with the gears. This seemed to work really well.
The video below shows that that the gears are working.
This next video shows that the bowl just starts to sing a the 1:2 gear ratio.
Things are looking better but there are still some design flaws I need to fix. First, the top platform is too close to the top of the bowl. There is not enough room for the servo to swing the mallet to touch the top rim of the bowl. Second, I think I need to print out 1:3 ratio gears. This will give me more room for adjustment of speed instead of having to run it at max RPM. Finally, I'll add supports for the rubber feet on the bottom. This helps reduce the amount of vibration and noise resonating through whatever it is sitting on.
I'll also do the next print all in one instead of breaking it into 3 separate parts.
Overall, things are getting better. The next rev3 I think will be the working model!